'Problem: Breathalyzers don't actually measure alcohol'

The vast majority of citizens arrested for drunk driving are tested for blood-alcohol on breath machines (generically referred to as "breathalyzers"). The test results from these machines will largely determine: (1) if the suspect is booked or released; (2) whether the driver's license is automatically suspended or not; (3) what charges, if any, will be filed by the prosecution; and (4) whether the the accused will be found guilty or not.

Problem: Breathalyzers don't actually measure alcohol.

Turns out that most breathalyzers are using infrared light to measure the presence of a methyl group that isn't limited to alcohol, and that builds up over time, leading to various false positive scenarios which the author of this opinion piece posits are potentially being ignored. Who might be at risk?

For starters, diabetics with low blood sugar can have high levels of acetone -- which is "seen" as alcohol by breathalyzers. And scientific studies have found that people on diets can have reduced blood-sugar levels, causing acetone hundreds of times higher than found in normal individuals.... If you are a smoker, to cite another example, your breathalyzer result is likely to be higher than expected. The compound acetaldehyde is one of those reported by breathalyzers as "alcohol", and researchers have discovered that levels of acetaldehyde in the lungs can be 30 times higher in smokers than in non-smokers. Result: higher blood-alcohol readings on the machine -- and citizens falsely convicted of drunk driving.

Ooops!